A clock starts running at 12:00 noon. At 5:10, the hour hand will have turned-

Explanation

∵ The angle made by the hour hand in each minute = $\frac{1^{\circ}}{2}$ The angle made by the hour hand in 5 hours 10 minutes i.e. 310 minutes = $310 \times \frac{1^{\circ}}{2} = 155^{\circ}$ Therefore, at 5:10, the hour hand will rotate 155⁰.